1. Field of the Invention
The present invention relates to a sheet handling apparatus comprising a plurality of inserter trays for inserting insert sheets between recording sheets having images formed thereon, an image forming apparatus, and a method of controlling the same and a storage medium therefor.
2. Description of Related Art
Conventionally, when a set of plural originals consisting of a mixture of plural kinds of originals, for example, a mixture of colored originals and black-and-white originals, are to be copied, a user uses a color copying machine and copies all the originals with the color copying machine to obtain desired duplications of the color/black-and-white mixed originals. However, since image forming processing with the color copying machine requires a longer time than with a black-and-white copying machine, it is inefficient to process any black-and-white originals with the color copying machine. Thus, there arises a demand for copying the black-and-white originals separately with a black-and-white copying machine, one way to meet the demand would be that when a mixture of colored originals and black-and-white originals are to be copied, color originals and black-and-white originals should be separately copied with a color copying machine and a black-and-white copying machine, respectively.
However, in such a separate copying, the user has to separate in advance the color/black-and-white mixed originals into color originals and black-and-white originals. After copying has been completed, the color originals and the black-and-white originals have to be restored to the initial condition. This is very complicated and time-consuming, especially when the originals are not paged or when the originals are large in number. Besides, after copying, in order to arrange the copied recording sheets output from the black-and-white copying machine and the copied recording sheets output from the color copying machine in the order of the originals, it is necessary, for example, to insert the copied recording sheets from the color copying machine between the copied recording sheets from the black-and-white copying machine. This requires a very complicated manual operation which has to be performed manually while checking the order of the originals.
Thus, the conventional manner of copying color/black-and-white mixed originals separately with a color copying machine and a black-and-white copying machine has the disadvantage that a very complicated manual operation needs to be carried out by a user and the operation is difficult to correctly perform without error as well as very time-consuming.
To overcome the above-mentioned disadvantage, an image forming apparatus has already been proposed which includes a plurality of copying machines, for example, a color copying machine and a black-and-white copying machine, and an inserter tray. The mixed originals are subjected to copying processing by means of a combination of these components. The inserter tray is constructed, in general, as a sheet feeding tray that permits an insert sheet which is to be inserted between recording sheets having image formed thereon by an image forming section to be conveyed without passing through the image forming section.
According to the proposed apparatus, it is automatically determined whether each original of a set of mixed originals is a color original or not. A color original is automatically copied with the color copying machine, and a black-and-white original is automatically copied with the black-and-white copying machine. An insert sheet to be inserted between recording sheets is fed from the inserter tray so as to improve the efficiency of the processing operation.
However, in the above-described image forming apparatus including the inserter tray, the method of feeding insert sheets from the inserter tray can be set to output modes such as a cover sheet mode and a synthesis mode, but the manner of loading the insert sheets on the inserter tray is fixed so that optimal processing is not always possible to perform.
More specifically, in order to perform a copying process of plural kinds of originals efficiently in the shortest time, it is required to comprehensively take into account the capability (number of bins, loading capacity, etc.) of the sheet discharging sections (sorters, finishers etc.) of the color/black-and-white copying machines, and the number of bins, loading capacity, etc. of the inserter tray, so as to perform the processing in an optimal operating mode. In the conventional apparatus, however, the two copying machines are unable to know the status of each other's sheet discharging section or inserter tray, and hence are forced to operate, not in the optimal operating mode, but in a predetermined operating mode. Therefore, there is room for improvement in processing efficiency and operability.